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its lower course, that is, east of Manaos, flows through a Devonian basin filled with rocks of later age. Near longitude 550-56° W., Devonian rocks outcrop on both sides of the stream a little more than a hundred miles away from it. It is improbable that this Devonian basin extends far up the Amazon valley, for there are metamorphic rocks on the Rio Negro, a short distance above Manaos. In the highlands of Matto Grosso, Brazil, just east of Cuyabfi, Devonian rocks cap the hills. Devonian beds are known in Bolivia along the eastern slope of the Andes, and it seems probable that they extend north and south along the range for a long distance. In the state of Parana, Brazil, a belt supposed to be of Devonian age crosses the state from north to south (Derby), dipping westward beneath a series of rocks referred to the Trias. The known areas of Carboniferous rocks in South America are small—one basin underlying the Lower Amazon valley contains marine fossils, having a Permian facies. Carboniferous rocks of about the same geological horizon are known also from the vicinity of Lake Titicaca in Bolivia. In the state of Sao Paulo, and extending into the adjacent states of Minas Geraes and Parana, is another Carboniferous or possibly Permian basin, but the fossils are scarce and are not marine. The western and southern limits of this Sao Paulo basin are not known at present. In the southernmost states of Brazil, namely, in Santa Catharina and Rio Grande do Sul, there are at least six separate South America. basins in which coal of Carboniferous age occurs. One Granites and gneisses, supposed to be of Archaean age, of these basins is on Rio Tubarao, near Laguna, Santa occur at many places along the east side of the Andes, in Catharina; another is on the Rio Verde, the line between Santa Catharina and Rio Grande do Sul. In Rio Grande highlands Venezuela near Geology. athe kout caracag.of There is a and more or the less coast con- do Sul there is one coal basin at Candiota on the railway tinuous area of granites along the watershed between the leading from Pelotas to Bage, another near the south end Amazon and Venezuela and the Guianas extending from of Arroyo dos Ratos, one 100 miles in length lies along the fall line on the Cunani, and the Araguay on the the south side of Rio Vacacahy, and another is just west east to the mouth of Rio Meta on the Orinoco, and of the city of Porto Alegre. Overlying the rocks of Carthe mouth of the Uauapes on Rio Negro. In this region boniferous or Permian age in Minas, Sao Paulo, and the granites are overlapped in many places by more recent Parana, Brazil, is a series of sediments and eruptives that beds of unknown age. In the highlands of Brazil south have been referred provisionally to the Triassic. Thus far of the Amazon they are found at the falls of the Madeira no fossils have been found in them. Rocks believed to be river, on the Tapajos, at the falls of the Xingii on the of Triassic age occur in Paraguay, near Diamantino, in the south side of the Amazon valley, and along the eastern states of Matto Grosso, Brazil, and in Chile and Bolivia. border of the continent, with certain short interruptions Jurassic rocks are found in Chile, Bolivia, Peru, and the from Maranhao, Brazil, southward to Montevideo, at the Argentine Republic, and it is possible that some of the mouth of the Rio de la Plata. The largest of these Brazilian rocks previously referred to the Triassic belong to granite areas is the one along the east coast and in the the Jurassic. Rocks of Cretaceous age cover a large area in the highlands of Eastern Brazil, but even here it is more or less irregular in outline, and its exact limits are unknown interior of the states of Ceara, Piauhy, Parahyba, and except on the immediate coast. Associated with the Pernambuco in Brazil, while on the coast of the states of granites and gneisses is a series of metamorphosed beds Sergipe and Alagoas there are Cretaceous beds containing exposed over a still larger area. These include schists of an abundance of marine fossils. Cretaceous rocks are found various kinds, itacolumites, itabirites, slates, quartzites, in Tierra del Fuego, in Southern Patagonia, in the province and marbles. The series is more or less folded, faulted, of Santa Cruz, Argentine Republic, and they extend veined, and cut by old eruptives. The age of these beds northward along the eastern flank of the Andes, with has never been definitely determined, for they have thus interruptions through Ecuador, Colombia, and Venezuela. far yielded no fossils. In many places they bear a strong On the west side of the Andes a narrow belt of Cretaceous resemblance to the Algonkian series of North America, extends nearly or quite the whole length of the continent. but their position would admit equally well of their refer- The coal or lignite beds of Southern Chile are in the ence to the Cambrian. In this series occur most of the Laramie of the upper Cretaceous. Cretaceous rocks cover a part of the island of Trinidad, off the north coast of mineral deposits of the eastern part of the continent the gold veins of Venezuela, of the Guiana highlands, Venezuela, and the same Cretaceous basin extends over a and of the gold regions of Brazil, and also the iron, part of the Venezuela mainland. The rocks of this age on Trinidad are of organic origin, and it is from these manganese, diamonds, and topazes of Brazil. Rocks of Silurian age have been found in the Amazon that the remarkable pitch deposits of that island have valley, on the north side of the river east of Manaos; in been derived. Eocene Tertiary beds occur on the island of Trinidad Bolivia, along the eastern slope of the Andes and near Cuyaba, about the headwaters of the Rio Paraguay. It and on the Venezuela mainland, but it is not known how is quite possible, even probable, that many of the un- far these beds extend to the south along the eastern fossiliferous beds, now provisionally referred to the border of the continent. Just south of the Rio Oyapok Cambrian, are of Silurian age. The Amazon river along granites are exposed on the lower courses of the streams,
industrious, and orderly class of men, but one which stands apart in language, religion, and race from the dominant population, lives largely without domestic ties, and gains neither political nor social standing in the New World. Two hundred years ago the aboriginal population of North America would have deserved description before the immigrant population. To-day the aborigines are displaced from all the most valuable parts of the continent. Never very numerous, they are now decreasing; many tribes are already extinct, many more are almost so. Those which remain less diminished are in the Far North or North-West, where nature is rigorous; or in the tropical forests of Central America where nature is overbounteous; or in the more desert parts of the Middle West where nature is arid. The replacement of the native races by the foreign has too often been harsh, cruel, and unjust; yet it has resulted in an advance of civilization. Many savage tribes, speaking many different languages, holding little intercourse with each other, and frequently engaged in intertribal wars, have given place in little more than two centuries to a great population of European origin, whose dominant parts speak one language, whose arts are highly advanced, whose home intercourse is most active, and whose foreign commerce has attained unexpected proportions at the opening of the 20th century. M D ^
